Gusset forming apparatus and bag-making / filling / packaging machine

Abstract

To provide a gusset forming device capable of easily replacing a gusset claw with a simple constitution and accurately positioning the gusset claw.SOLUTION: The gusset forming device includes a slide shaft extending in a first direction perpendicular to the conveying direction, a gusset claw unit configured to move in the first direction along the slide shaft, and an actuator configured to push and pull the gusset claw unit in the first direction, the gusset claw unit includes a frame connected to the actuator, a gusset claw fixed to the frame with a tip thereof facing the belt-shaped packaging material and configured to be pushed and pulled by the actuator to form a gusset in the belt-shaped packaging material, and a slide bearing fixed to the frame and fitted to the slide shaft to guide movement of the gusset claw unit in the first direction, the gusset claw unit is configured such that the slide bearing can be inserted into and removed from the slide shaft in a state where the frame, the gusset claw, and the slide bearing are integrated with each other.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a gusset forming device and a form-fill-seal packaging machine. [Background technology]

[0002] Conventionally, form-fill-seal machines are equipped with a center seal device that seals both ends of a stacked strip of film, and an end seal device that seals both ends of the strip of film formed into a cylindrical shape by the center seal device, in the conveying direction. The end seal device includes a pair of seal blocks and a contact / separation mechanism that moves the pair of seal blocks toward each other. The contact / separation mechanism moves the pair of seal blocks toward each other, sandwiching the strip of film between them to form an end seal.

[0003] Furthermore, the end sealing device is equipped with a gusset forming device that forms gussets in the packaging bag (see, for example, Patent Document 1). A gusset is a fold that is formed on the side of the packaging bag near the end seal. The gusset is formed to allow more product to be filled into the packaging bag or to make it easier to stand the packaging bag upright.

[0004] The gusset forming device includes a gusset claw that forms the gussets and a drive mechanism that drives the gusset claw. When the end seal device applies end seals to the film strip, the gusset claw presses the sides of the film strip into the cylindrical shape to form gussets. Therefore, the drive mechanism of the gusset forming device moves the gusset claw in accordance with the movement of the pair of seal blocks described above. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-206726 Summary of the Invention [Problem to be solved by the invention]

[0006] In a gusset forming device, the gusset claws are detachable so that they can be easily replaced depending on the dimensions of the packaging bag and the gusset. However, in a conventional configuration, the gusset claws are positioned by simply inserting a pin protruding from a frame into a recess provided in a gusset claw holder, which causes play between the recess and the pin. As a result, there is a problem in that the positioning accuracy of the gusset claws is reduced.

[0007] The present invention has been made to solve the above problems, and its object is to provide a gusset forming device that allows gusset claws to be easily replaced and more accurately positioned. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, the present invention provides a gusset forming device that forms gussets in a strip packaging material in accordance with the approaching and separating movement of a pair of seal blocks that seal a cylindrical strip packaging material on both sides in the conveying direction, and is characterized in that it comprises a slide shaft extending in a first direction perpendicular to the conveying direction, a gusset claw unit that moves in the first direction along the slide shaft, and an actuator that pushes and pulls the gusset claw unit in the first direction, and the gusset claw unit comprises a frame connected to the actuator, gusset claws that are fixed to the frame with their tips facing the strip packaging material and are pushed and pulled by the actuator to form gussets in the strip packaging material, and a slide bearing that is fixed to the frame and engaged with the slide shaft to guide the movement of the gusset claw unit in the first direction, and the gusset claw unit is configured so that the slide bearing can be inserted and removed from the slide shaft when the frame, gusset claws, and slide bearing are integrated. [Effects of the Invention]

[0009] According to the present invention, a gusset forming device can be obtained that allows for easy replacement of gusset claws and more accurate positioning. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a side view of a horizontal form-fill-seal packaging machine. [Figure 2] FIG. 1 is a plan view of a horizontal form-fill-seal packaging machine. [Figure 3] FIG. 2 is a front perspective view of the end seal device. [Figure 4] FIG. 2 is a rear perspective view of the end seal device. [Figure 5] FIG. 2 is an exploded perspective view showing the configuration of a gusset forming device. [Figure 6] FIG. 2 is a side view of the gusset forming device. [Figure 7] 7 is a cross-sectional view of a main part of the gusset forming device taken along line VII-VII in FIG. 6. [Figure 8] FIG. 2 is a perspective view showing the configuration of a gusset claw unit. [Figure 9] 10A and 10B are explanatory views showing the operation of the gusset forming device and the sealing device, and are explanatory views showing the operation of switching the plate cam and the cam follower from a released state (A) to an engaged state (B). [Figure 10] 10A and 10B are explanatory views showing the operation of the gusset forming device and the sealing device, and are explanatory views showing the operation of the gusset claws being displaced from a retreated position (A) to an advanced position (B). [Figure 11] 10 is an explanatory diagram showing the operation of the gusset forming device and the sealing device, and is an explanatory diagram showing the operation of switching the plate cam and the cam follower to a release state after the gusset is formed. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] [Overall configuration of horizontal form-fill-seal packaging machine 10] A horizontal form-fill-seal packaging machine 10 to which the gusset forming device of the present invention is applied will be described below with reference to the drawings. Note that the embodiment of the present invention described below is an example of how the present invention can be realized, and the scope of the present invention is not limited to the scope of the described embodiment. Therefore, the present invention can be implemented by adding various modifications to the embodiment.

[0012] Fig. 1 is a side view of a horizontal form-fill-seal packaging machine 10. Fig. 2 is a plan view of the horizontal form-fill-seal packaging machine 10. The horizontal form-fill-seal packaging machine 10 (form-fill-seal packaging machine) is a device that packages products P supplied from a supply device (not shown) one by one. As shown in Figs. 1 and 2, the horizontal form-fill-seal packaging machine 10 mainly comprises a supply conveyor 11, a packaging material feeder 20, a cylinder former 29, a clamping and conveying device 30, a center sealing device 35 (first sealing device), and an end sealing device 40 (second sealing device).

[0013] The supply conveyor 11 supplies products P, which are sequentially supplied from a supply device (not shown), to the cylinder former 29. As shown in FIG. 1, the supply conveyor 11 is made up of a drive sprocket 14, a driven sprocket 15, an endless circular conveyor chain 16 stretched between the drive sprocket 14 and the driven sprocket 15, and a drive motor 17 that drives the drive sprocket 14.

[0014] The conveyor chain 16 is also provided with a plurality of pushers 18. The pushers 18 are arranged at predetermined intervals in the conveying direction of the products P. A product P supplied from a supply device enters between two adjacent pushers 18. The pushers 18 come into contact with the rear end of the product P and push the product P.

[0015] The packaging material feeding device 20 feeds a strip-shaped film Fw (strip-shaped packaging material) toward the clamping and conveying device 30. As shown in Figures 1 and 2, the packaging material feeding device 20 includes a holder unit 21 that holds a film roll Fr (packaging material roll) formed by winding the strip-shaped film Fw around a core into a roll, a drive roller 22, a driven roller 23, a feed motor 24, and guide rollers 25a and 25b.

[0016] The strip film Fw is a strip-shaped packaging material that is used to make bags for packaging products. The strip film Fw is a film-like member that can be welded by applying heat, and examples include polyethylene (PE), polyethylene terephthalate (PET), biaxially oriented polypropylene (OPP), aluminum-lined paper, and aluminum-metalized paper. The product refers to food such as cookies and dorayaki. However, specific examples of the product are not limited to these and include any item that is packaged in a bag Bp and shipped.

[0017] The drive roller 22 and the driven roller 23 rotate while sandwiching the strip film Fw. The drive roller 22 rotates when the driving force of the feed motor 24 is transmitted to it. As a result, the drive roller 22 and the driven roller 23 pay out the strip film Fw wound around the holder unit 21 toward the tube former 29. The guide rollers 25a and 25b are arranged along the transport path of the strip film Fw from the holder unit 21 through the drive roller 22 and driven roller 23 to the tube former 29, and apply tension to the strip film Fw as it is paid out.

[0018] The cylinder former 29 forms the strip film Fw fed by the packaging material feeding device 20 into a cylindrical shape, and serves as an entrance through which the products P fed from the supply conveyor 11 enter the cylindrical strip film Fw. The cylinder former 29 is disposed on the transport path of the strip film Fw from the packaging material feeding device 20 to the center seal device 35. The cylinder former 29 is disposed facing the downstream end of the supply conveyor 11 in the transport direction.

[0019] The strip film Fw fed by the packaging material feeding device 20 is formed into a cylindrical shape by overlapping both ends in the width direction perpendicular to the conveying direction below as it moves along the cylinder former 29. In addition, the product P fed from the supply conveyor 11 passes through the internal space of the cylinder former 29 and enters the inside of the cylindrical strip film Fw.

[0020] The clamping and conveying device 30 clamps the overlapped ends of the strip film Fw formed into a cylindrical shape by the cylinder former 29 and conveys it in the conveying direction. The clamping and conveying device 30 is located downstream in the conveying direction from the cylinder former 29. The clamping and conveying device 30 is also located below the strip film Fw and product P that have passed through the cylinder former 29. The clamping and conveying device 30 mainly comprises a support plate 31, a pair of film feed rollers 32, 33, and a feed motor 34.

[0021] The support plate 31 is connected downstream in the conveying direction from the cylinder former 29. The support plate 31 supports the product P contained in the cylindrical strip film Fw. The support plate 31 also extends in the conveying direction up to the position of the center seal device 35. Furthermore, the support plate 31 has a slit 39 that extends through the center of the width direction along the conveying direction of the strip film Fw. The overlapped ends of the strip film Fw protrude from the underside of the support plate 31 through the slit 39.

[0022] A pair of film feed rollers 32, 33 are disposed on the underside of the support plate 31. The pair of film feed rollers 32, 33 clamp the overlapping ends of the strip film Fw protruding through the slit 39. The film feed roller 32 rotates by the driving force transmitted from the feed motor 34. As a result, the cylindrical strip film Fw is transported in the transport direction toward the center seal device 35.

[0023] The center seal device 35 seals both widthwise ends of the strip film Fw that has been laminated by the cylinder former 29. The center seal device 35 is located downstream in the conveying direction from the cylinder former 29 and the clamping and conveying device 30. The center seal device 35 is also located below the strip film Fw and the product P (in other words, the support plate 31). The center seal device 35 mainly comprises a pair of sealing rollers 36, 37 and a sealing motor 38.

[0024] The pair of sealing rollers 36, 37 are disposed on the underside of the support plate 31, downstream of the film feed rollers 32, 33 in the transport direction of the strip film Fw. The pair of sealing rollers 36, 37 clamp the overlapped ends of the strip film Fw protruding through the slit 39. The outer peripheral surfaces of the sealing rollers 36, 37 are heated by a heater (not shown). The driving force of a sealing motor 38 is transmitted to the sealing roller 36, causing it to rotate. This seals (welds) the overlapped ends of the strip film Fw clamped between the sealing rollers 36, 37.

[0025] The end sealing device 40 is disposed downstream in the conveying direction from the tube former 29, the clamping and conveying device 30, and the center sealing device 35. The end sealing device 40 seals the tubular strip film Fw sealed by the center sealing device 35 on both sides of the product P in the conveying direction, thereby forming a bag Bp filled with the product P.

[0026] [Configuration of end seal device 40] As shown in Figures 3 and 4, the end seal device 40 includes a pair of seal blocks 41, 42, holders 43, 44, guide shafts 45L, 45R, a contact / separation mechanism 46 (see Figures 9 to 11), gusset forming devices 47L, 47R, a support block 48, and a control device 49 (see Figures 9 to 11).

[0027] In this embodiment, the width direction in Figures 1 and 2 corresponds to the "first direction," the conveying direction corresponds to the "second direction," and the vertical direction corresponds to the "third direction." However, the correspondence between the first to third directions is not limited to the example described above, and they may be perpendicular to each other. Furthermore, the second and third directions may be the same direction. Furthermore, in the vertical direction, the side facing the holder 43 from the strip film Fw being conveyed is defined as "upper," and the opposite side is defined as "lower."

[0028] The guide shafts 45L, 45R are provided at positions spaced apart in the width direction and extend in the vertical direction, and are supported by a support block 48 so that they can move up and down. The guide shafts 45L, 45R also support a pair of seal blocks 41, 42 and holders 43, 44.

[0029] Holder 43 is fixed to the upper ends of guide shafts 45L and 45R. Holder 43 supports seal block 41 on its lower surface. Holder 44 is supported below holder 43 on guide shafts 45L and 45R so as to be movable up and down. Holder 44 supports seal block 42 on its upper surface. That is, seal blocks 41 and 42 are arranged facing each other in the vertical direction.

[0030] The sealing blocks 41, 42 are arranged facing each other in the vertical direction, sandwiching the cylindrically formed strip film Fw therebetween. The sealing blocks 41, 42 also extend in the width direction. That is, the longitudinal direction of the sealing blocks 41, 42 coincides with the width direction of the horizontal form-fill-seal-seal machine 10. The surfaces of the sealing blocks 41, 42 that face the strip film Fw are heated by a heater (not shown). The sealing blocks 41, 42 are brought into contact with and separated from each other by the drive of a contact / separation mechanism 46. The end sealing device 40 brings the sealing blocks 41, 42 into contact with each other between adjacent products P. This causes the portions of the strip film Fw sandwiched between the sealing blocks 41, 42 to be sealed (welded) between the adjacent products P.

[0031] The support block 48 is fixed to the frame of the horizontal form-fill-seal packaging machine 10. The support block 48 also supports the guide shafts 45L, 45R below the holder 44 so that they can move up and down. The support block 48 also supports the contact / separation mechanism 46. The support block 48 is composed of, for example, a base plate 51 and a pair of cylindrical bodies 52L, 52R.

[0032] The base plate 51 extends horizontally. The base plate 51 is fixed to the frame of the horizontal form-fill-seal packaging machine 10. The cylindrical bodies 52L, 52R are cylindrical portions that are open at both axial ends. The cylindrical bodies 52L, 52R are fixed to the base plate 51 at positions surrounding through-holes (not shown) that penetrate the base plate 51 in the thickness direction. The cylindrical bodies 52L, 52R extend vertically. The guide shafts 45L, 45R are inserted into the cylindrical bodies 52L, 52R and are guided by the cylindrical bodies 52L, 52R to move up and down.

[0033] The contacting and separating mechanism 46 converts, for example, the rotation of a drive motor into linear motion and transmits it to the seal blocks 41, 42. The contacting and separating mechanism 46 pushes and pulls the seal blocks 41, 42 in the vertical direction under control, causing the seal blocks 41, 42 to contact and separate in the vertical direction. Note that the configuration of the contacting and separating mechanism 46 is not limited to this, and for example, it may be configured to push and pull the seal blocks 41, 42 in the vertical direction using an actuator such as an air cylinder. The control device 49 controls the drive motor or actuator of the contacting and separating mechanism 46. Note that the control device 49 controls the contacting and separating mechanism 46 as well as the actuators 65 of the gusset forming devices 47L, 47R, which will be described later.

[0034] Although not shown, the end sealing device 40 also includes a cutting device. The cutting device cuts the strip film Fw. More specifically, the cutting device cuts the sealed portion of the strip film Fw sealed by the end sealing device 40 (i.e., the boundary portion between adjacent bags Bp).

[0035] [Configuration of gusset forming device 47L] 5, the gusset forming device 47L includes a plate cam 61, a fixed frame 62, two slide shafts 63A and 63B, a gusset claw unit 64, and an actuator 65. Although not shown in detail, the gusset forming device 47R has the same configuration as the gusset forming device 47L, and is disposed on both sides of the seal blocks 41 and 42 in the width direction, symmetrically to the gusset forming device 47L.

[0036] [Configuration of Plate Cam 61] 6 and 7, the plate cam 61 is fixed to one end of the holder 44 in the width direction. Specifically, the plate cam 61 is fastened to the holder 44 by a screw 66. As a result, when the seal blocks 41, 42 move toward or away from each other in the vertical direction, the plate cam 61 moves in conjunction with one of the seal blocks 42 and the holder 44. More specifically, the plate cam 61 moves upward when the seal blocks 41, 42 move toward each other, and moves downward when the seal blocks 41, 42 move away from each other.

[0037] The plate cam 61 has a sliding surface 67. The sliding surface 67 has an outer sliding surface 67A, an inclined surface 67B, and an inner sliding surface 67C. The outer sliding surface 67A and the inner sliding surface 67C are surfaces that are perpendicular to the width direction and extend in the vertical direction. The outer sliding surface 67A is located at the uppermost position and on the outer side in the width direction among the sliding surfaces 67. The inner sliding surface 67C is located at the lowermost position and on the inner side in the width direction among the sliding surfaces 67.

[0038] The inclined surface 67B is a surface that connects the lower end of the outer sliding contact surface 67A and the upper end of the inner sliding contact surface 67C. In other words, the inclined surface 67B is a surface that slopes downward toward the strip film Fw in the width direction. The inclined surface 67B is inclined at, for example, 45° with respect to the up-down direction. The sliding contact surface 67 is engaged with and disengaged from a cam follower 72, which will be described later, by pushing and pulling the actuator 65.

[0039] The fixed frame 62 is fixed to the support block 48. Specifically, the fixed frame 62 is fastened to the cylindrical body 52L with screws (not shown). However, this is not limiting, and the fixed frame 62 and the cylindrical body 52L may be formed integrally. The fixed frame 62 extends in the vertical direction. Slide shafts 63A, 63B and an actuator 65 are fixed to the fixed frame 62.

[0040] [Configuration of slide shafts 63A and 63B] The slide shafts 63A, 63B extend in the width direction. More specifically, the slide shafts 63A, 63B extend from the fixed frame 62 to the side opposite the seal blocks 41, 42 (in other words, the strip film Fw). The slide shafts 63A, 63B are formed in a cylindrical shape with a circular or elliptical cross section, and one end on the inner side in the width direction is fastened to the fixed frame 62 with a screw 68 (see FIG. 7). The slide shafts 63A, 63B are guide shafts that support the slide bearings 73A, 73B so that they can slide in the width direction. The slide shafts 63A, 63B are members processed by hardening a metal such as iron, and are members with higher precision and durability than the other constituent members. In addition, in this embodiment, the gusset forming device 47L is equipped with two slide shafts 63A and 63B, so the slide bearings 73A and 73B do not rotate around the slide shafts 63A and 63B, and there is no need to provide a separate member to restrict rotation.

[0041] The slide shafts 63A and 63B are aligned in the width direction (parallel to each other) and are arranged at a predetermined interval in the vertical direction. The gusset claw units 64 are attached to the slide shafts 63A and 63B. The gusset claw units 64 move in the width direction along the slide shafts 63A and 63B.

[0042] The actuator 65 is disposed between the two slide shafts 63A and 63B in the vertical direction. The actuator 65 is, for example, an air cylinder, and a piston rod 65A advances and retreats in the width direction in response to the supply and exhaust of air. More specifically, the piston rod 65A protrudes outward in the width direction when air is supplied, and retreats inward in the width direction when air is exhausted. The piston rod 65A is disposed so that the direction in which it advances and retreats coincides with the direction in which the slide shafts 63A and 63B extend.

[0043] On the other hand, the direction in which the piston rod 65A advances and retreats may be slightly misaligned with the direction in which the slide shafts 63A and 63B extend due to dimensional errors of the actuator 65 and the slide shafts 63A and 63B, and errors in assembling the actuator 65 and the slide shafts 63A and 63B relative to the fixed frame 62. Such misalignment in direction is absorbed by the connection between the gusset claw unit 64 and a connecting member 69, which will be described later.

[0044] The actuator 65 includes a connecting member 69. The connecting member 69 is coupled to one end (tip) of the piston rod 65A on the outer side in the width direction. The connecting member 69 is formed in a substantially rectangular plate shape and extends in a direction perpendicular to the conveying direction. The connecting member 69 has a through hole 69A and a positioning protrusion 69B. The through hole 69A penetrates the connecting member 69 in the conveying direction. A plunger pin 75A of a plunger 75 (described later) is inserted into the through hole 69A. A gap is formed between the outer peripheral surface of the plunger pin 75A and the inner peripheral surface of the through hole 69A. The positioning protrusion 69B is a protrusion that protrudes upward and downward from the outer shape of the connecting member 69. The connecting member 69 is connected to a frame 74 of a gusset claw unit 64 (described later).

[0045] [Configuration of Gusset Claw Unit 64] 7 and 8, the gusset pawl unit 64 includes a gusset pawl 71, a cam follower 72, slide bearings 73A and 73B, a frame 74, and a plunger 75. The frame 74 supports the gusset pawl 71, the cam follower 72, and the slide bearings 73A and 73B.

[0046] [Frame 74 Configuration] The frame 74 includes a gusset claw support portion 74A and a bearing support portion 74B. The frame 74 is formed in an L-shape with the gusset claw support portion 74A and the bearing support portion 74B intersecting at right angles. The gusset claw support portion 74A is formed linearly and extends in the conveying direction. The gusset claw support portion 74A supports the gusset claw 71. The bearing support portion 74B is formed linearly and extends in the vertical direction. The bearing support portion 74B supports the slide bearings 73A and 73B.

[0047] The bearing support portion 74B is formed with a connection hole 74C, a female threaded hole 74D, and a through hole 74E. The connection hole 74C is disposed between the slide bearings 73A and 73B and is a through hole that penetrates the bearing support portion 74B in the width direction. A connection member 69 is inserted into the connection hole 74C. The connection hole 74C is formed larger than the connection member 69 in the vertical and conveying directions. That is, a gap is formed between the outer surface of the connection member 69 that has entered the connection hole 74C and the inner wall that defines the connection hole 74C. This allows the plunger pin 75A to be easily inserted into the through hole 69A for the connection member 69 that has been inserted into the connection hole 74C and positioned by the positioning protrusion 69B. The female threaded hole 74D extends in the conveying direction from the upstream end face of the bearing support portion 74B in the conveying direction and communicates with the connection hole 74C.

[0048] [Configuration of gusset claw 71] The gusset claw 71 includes a pair of claw portions 76A, 76B and a connecting member 77. The connecting member 77 is formed in a U-shape, and the claw portions 76A, 76B are fixed to both ends. In other words, the connecting member 77 supports the claw portions 76A, 76B. The connecting member 77 is fastened to a gusset claw support portion 74A of the frame 74 by a screw 78. As a result, the gusset claw 71 is fixed (integrated) with the frame 74.

[0049] The claw portions 76A and 76B are arranged on both sides of the sealing blocks 41 and 42 in the conveying direction. Specifically, the claw portion 76A is located downstream of the sealing blocks 41 and 42 in the conveying direction, and the claw portion 76B is located upstream of the sealing blocks 41 and 42. The gusset claw 71 is fixed to the frame 74 with the tips of the claw portions 76A and 76B facing the side of the cylindrically formed strip film Fw. The tips of the claw portions 76A and 76B are bent toward the sealing blocks 41 and 42.

[0050] [Configuration of Cam Follower 72] The cam follower 72 is formed in a disk shape. The cam follower 72 is arranged to align with the position of the sliding surface 67 of the plate cam 61 in the vertical direction and the conveying direction. The cam follower 72 is supported by the frame 74 so as to be rotatable about a rotation shaft 72A that is arranged parallel to the conveying direction.

[0051] The cam follower 72 can be switched between an engaged state in which it engages with the plate cam 61 and a released state in which it is disengaged from the plate cam 61 by pushing and pulling the actuator 65 connected to the frame 74. More specifically, when the piston rod 65A of the actuator 65 moves the frame 74 inward in the width direction, the outer circumferential surface of the cam follower 72 presses against the plate cam 61, entering an engaged state. On the other hand, when the piston rod 65A of the actuator 65 moves the frame 74 outward in the width direction, the outer circumferential surface of the cam follower 72 moves away from the plate cam 61, entering a released state in which it is disengaged.

[0052] [Configuration of slide bearings 73A and 73B] 7 and 8, the slide bearings 73A and 73B are arranged parallel to each other and aligned in the vertical direction. The slide bearings 73A and 73B are arranged in alignment with the slide shafts 63A and 63B. Each of the slide bearings 73A and 73B includes a cylindrical portion 81A, a flange portion 81B, and a plurality of rolling elements (not shown). The axial direction of the cylindrical portions 81A of the slide bearings 73A and 73B extends in the width direction.

[0053] The slide bearings 73A and 73B are linear bushings with multiple rolling elements arranged along the width direction on the inner circumferential surface of the cylindrical portion 81A. The inner circumferential surface of the cylindrical portion 81A slides against the outer circumferential surfaces of the slide shafts 63A and 63B, respectively. This allows the slide bearings 73A and 73B to fit with the slide shafts 63A and 63B so that they can move in the width direction. The slide bearings 73A and 73B can be inserted and removed from the slide shafts 63A and 63B. Like the slide shafts 63A and 63B, the slide bearings 73A and 73B are made of highly accurate and durable materials. Furthermore, there is almost no gap or backlash between the slide bearings 73A and 73B and the slide shafts 63A and 63B. This allows for high precision in positioning the gusset pawls 71 relative to the slide shafts 63A and 63B, as described below.

[0054] The cylindrical portion 81A passes through the through-hole 74E of the bearing support portion 74B. The flange portion 81B protrudes from the outer end surface of the cylindrical portion 81A in the width direction. The end surface of the flange portion 81B when viewed from the width direction is oval, that is, its outer shape is such that upper and lower arc shapes are connected by straight lines on both sides. The flange portion 81 is fastened to the outer side of the bearing support portion 74B in the width direction by screws 82. As a result, the slide bearings 73A, 73B are fixed (integrated) to the frame 74.

[0055] [Plunger 75 Configuration] The plunger 75 includes a plunger pin 75A, a coil spring 75B (biasing member), a case 75C, and a knob 75D. The case 75C extends in the conveyance direction. A male thread 75E is formed on the outer peripheral surface of the tip of the case 75C in the conveyance direction. The male thread 75E is threadedly engaged with a female threaded hole 74D of the frame 74. As a result, the plunger 75 is fastened to the frame 74 and disposed in a position facing the connection hole 74C.

[0056] The plunger pin 75A is positioned so as to be aligned with the through hole 69A of the connection member 69 inserted into the connection hole 74C. The plunger pin 75A is provided so as to be able to protrude and retract between a protruding position where it protrudes into the connection hole 74C along the conveyance direction and a retracted position where it retracts from the connection hole 74C. The plunger pin 75A is inserted into the through hole 69A of the connection member 69. The through hole 69A is formed to be larger in dimensions than the plunger pin 75A in the up-down direction and width direction. In other words, a gap is formed between the outer surface of the plunger pin 75A inserted into the through hole 69A and the inner wall that defines the through hole 69A.

[0057] Coil spring 75B biases plunger pin 75A toward the protruding position. For convenience of illustration, coil spring 75B is shown schematically outside case 75C, but in reality, it is incorporated inside case 75C and biases plunger pin 75A. Knob 75D is provided integrally with plunger pin 75A. By pulling knob 75D relative to case 75C, plunger pin 75A moves to the retracted position against the biasing force of coil spring 75B.

[0058] [Attachment and detachment process of the gusset claw unit 64 to the slide shafts 63A and 63B] The gusset claw unit 64 is replaced with one having claw portions 76A, 76B of different dimensions depending on the dimensions of the packaging bag and gusset. In the process of attaching the gusset claw unit 64 to the slide shafts 63A, 63B, first, an operator inserts the slide bearings 73A, 73B of the gusset claw unit 64 from the tip ends (outsides) of the slide shafts 63A, 63B in the width direction. This restricts the position of the gusset claw unit 64 in the conveying direction and up and down relative to the seal blocks 41, 42.

[0059] Furthermore, when the gusset claw unit 64 is pushed inward in the width direction, i.e., toward the film strip Fw, along the slide shafts 63A and 63B, the connecting member 69 of the actuator 65 is inserted into the connecting hole 74C of the frame 74. At this time, the operator operates the knob 75D to move the plunger pin 75A from the protruding position to the retracted position. Furthermore, as the connecting member 69 is inserted into the connecting hole 74C, the positioning protrusion 69B abuts against the bearing support portion 74B of the frame 74. This positions the connecting member 69 relative to the frame 74. More specifically, the abutment of the positioning protrusion 69B and the bearing support portion 74B allows the connecting member 69 to be positioned so that the plunger pin 75A can be guided into the through hole 69A.

[0060] After the insertion of the connecting member 69 into the connecting hole 74C is completed and the connecting member 69 is positioned relative to the bearing support portion 74B, the operator releases the knob portion 75D, and the plunger pin 75A moves from the retracted position to the protruding position due to the bias of the coil spring 75B. This causes the plunger pin 75A to be inserted into the through hole 69A of the connecting member 69. The plunger pin 75A enters the through hole 69A with a gap formed between the plunger pin 75A and the inner wall that defines the through hole 69A. Then, the insertion of the plunger pin 75A into the through hole 69A prevents the connecting member 69 from coming off the frame 74. In other words, the connecting member 69 is connected to the frame 74.

[0061] As described above, the position of the gusset claw unit 64 in the conveying direction and the up-down direction relative to the seal blocks 41 and 42 is restricted by the engagement between the slide shafts 63A and 63B and the slide bearings 73A and 73B. Furthermore, the position of the gusset claw unit 64 in the width direction relative to the seal blocks 41 and 42 is restricted by the connection between the frame 74 and the connecting member 69. This allows the gusset claw unit 64 to be attached to the slide shafts 63A and 63B. Furthermore, the actuator 65 and the frame 74 are connected, allowing the actuator 65 to push and pull the gusset claw unit 64 in the width direction.

[0062] Next, in the process of removing the gusset claw unit 64 from the slide shafts 63A and 63B, the worker operates the knob 75D to move the plunger pin 75A from the protruding position to the retracted position. This releases the connection between the frame 74 and the connecting member 69. The gusset claw unit 64 is no longer restricted in its widthwise position relative to the seal blocks 41 and 42. This allows the slide bearings 73A and 73B to be inserted into and removed from the slide shafts 63A and 63B. In other words, the gusset claw unit 64 can be removed from the slide shafts 63A and 63B.

[0063] [Operation of the end seal device 40 and the gusset forming devices 47R and 47L] The operations of the end sealing device 40 and the gusset forming devices 47R, 47L, i.e., the gusset forming process and the end sealing process, will be described with reference to Figures 9 to 11. Figures 9 to 11 are views of the end sealing device 40 and the gusset forming devices 47R, 47L as viewed from the downstream side in the conveyance direction.

[0064] In the gusset forming process and end sealing process, first, the control device 49 controls the actuator 65 to operate the piston rod 65A and move the frame 74 from the outside to the inside in the width direction. This switches the cam follower 72 and the plate cam 61 from a disengaged state (the state shown in FIG. 9(A)) to an engaged state (the state shown in FIG. 9(B)). At this time, the movement of the frame 74 is restricted by the plate cam 61. The control device 49 controls the actuator 65 to pull the frame 74 inward in the width direction until the timing when the gusset is formed on the side of the strip film Fw. During this time, the engaged state between the plate cam 61 and the cam follower 72 is maintained.

[0065] The control device 49 controls the contacting / separating mechanism 46 in parallel with controlling the actuator 65, and moves the seal blocks 41, 42 in directions approaching each other toward the sealing position P0 (the position indicated by the dotted lines in FIGS. 9(A), 9(B), and 10(A)). As a result, the plate cam 61 moves upward in conjunction with one of the seal blocks 42. As described above, the movement of the frame 74, which is pulled inward in the width direction by the actuator 65, is restricted by the engagement state between the plate cam 61 and the cam follower 72. Specifically, when the plate cam 61 starts to move upward, the cam follower 72 is in sliding contact with the outer sliding surface 67A of the sliding surface 67, and therefore the movement of the frame 74 inward in the width direction is restricted.

[0066] As the seal block 42 continues to move upward, the plate cam 61 also moves upward in conjunction with it. As a result, the position at which the cam follower 72 slides switches from the outer sliding contact surface 67A to the inclined surface 67B (the state shown in FIG. 10(A)). Because the inclined surface 67B slopes inward in the width direction as it moves downward, the frame 74 is able to move inward in the width direction. Therefore, in time with the movement of the seal block 42, the gusset claw unit 64, including the gusset claw 71, cam follower 72, and frame 74, advances toward the side of the strip of film Fw.

[0067] While the cam follower 72 is in sliding contact with the inclined surface 67B, the gusset claw unit 64 moves forward, following the inclined surface 67B of the plate cam 61, in accordance with the upward movement of the seal block 42. As a result, the tips of the claw portions 76A, 76B of the gusset claw 71 move forward toward both side surfaces of the strip film Fw.

[0068] Then, just before the seal blocks 41 and 42 reach the sealing position P0, the sliding contact position of the cam follower 72 switches from the inclined surface 67B to the inner sliding contact surface 67C. This restricts the frame 74 from moving inward in the width direction (the state shown in Figure 10(B)). At this time, the tips of the claw portions 76A and 76B of the gusset claw 71 push the sides of the cylindrically formed strip film Fw inward in synchronization with the seal blocks 41 and 42. This allows the gusset forming devices 47R and 47L to form good gussets. Then, the seal blocks 41 and 42 reach the sealing position P0. As a result, the seal blocks 41 and 42 sandwich the strip film Fw from above and below to form end seals. In other words, gussets can be formed in the strip film Fw in accordance with the contact and separation movements of the seal blocks 41 and 42.

[0069] As shown in Figure 11, immediately after forming gussets and end seals on the strip film Fw, the control device 49 operates the piston rod 65A of the actuator 65 to move the frame 74 from the inside to the outside in the width direction. This switches the cam follower 72 and the plate cam 61 from an engaged state to a disengaged state. The gusset claw unit 64 then retracts from the side of the strip film Fw. This prevents defects such as the gusset claws 71 getting caught on the strip film Fw. From the state shown in Figure 11, the control device 49 controls the contact / separation mechanism 46 to move the seal blocks 41, 42 in the separation direction.

[0070] [Effects of the embodiment] According to the above embodiment, the gusset claw unit 64 is configured such that the gusset claw 71, frame 74, and slide bearings 73A and 73B are integrated together, and the slide bearings 73A and 73B are insertable and removable from the slide shafts 63A and 63B. Therefore, the gusset claw unit 64 is positioned by the slide shafts 63A and 63B and the slide bearings 73A and 73B, which are highly accurate components. This improves the positioning accuracy of the gusset claw 71. Furthermore, as a result, the gusset claw unit 64 can be easily replaced to use a gusset claw 71 that matches the dimensions of the packaging bag and gusset. Furthermore, the slide shafts 63A and 63B are highly durable components, which helps prevent a decrease in positioning accuracy.

[0071] In a configuration in which a pin protruding from a frame is inserted into a recess provided in the gusset claw holder to position the claw, as in conventional gusset forming devices, the gusset claw is long and heavy compared to the pin, so the tip of the gusset claw may sag due to gravity.However, in this embodiment, the gusset claw 71 is fixed to the frame 74 and is positioned with high precision as described above, so the tip of the gusset claw 71 will not sag.

[0072] Furthermore, by inserting the connecting member 69 into the connecting hole 74C of the frame 74 and the plunger pin 75A into the through hole 69A of the connecting member 69, the connecting member 69 is prevented from coming off the frame 74. This allows for easy connection between the frame 74 and the actuator 65. Furthermore, the plunger pin 75A enters the through hole 69A with a gap formed between it and the inner wall defining the through hole 69A, preventing the connecting member 69 from coming off the connecting hole 74C. This allows the gusset claw unit 64 to slide smoothly even if there is a misalignment between the direction in which the piston rod 65A advances and retreats and the direction in which the slide shafts 63A and 63B extend. This eliminates the need for a separate component, such as a floating joint, to absorb the directional misalignment. Furthermore, because the gusset claw unit 64 can slide smoothly, the load on the actuator 65 can be reduced, improving durability.

[0073] Furthermore, because the actuator 65 is located between the two slide shafts 63A and 63B in the vertical direction, the moment generated around the slide shafts 63A and 63B can be suppressed. This allows the gusset claw unit 64 to move stably in the width direction. If the actuator 65 were located at a position other than between the slide shafts 63A and 63B in the conveying direction or the vertical direction, the gusset claw unit 64 would be pulled in the direction in which the actuator 65 operates, generating a moment around the slide shafts 63A and 63B. However, this does not occur in this embodiment. Furthermore, because the slide bearings 73A and 73B are linear bushings with multiple rolling elements arranged along the width direction, the gusset claw unit 64 can move smoothly in the width direction.

[0074] In addition, the gusset claw 71 is composed of a pair of claw portions 76A, 76B and a connecting member 77 that supports the claw portions 76A, 76B and is fixed to the frame 74, and the claw portions 76A, 76B are arranged on both sides of the seal blocks 41, 42 in the conveying direction, so that gussets can be formed simultaneously on both sides of the downstream and upstream sides of the end seal portion of the strip film Fw in the conveying direction.

[0075] In the above embodiment, the gusset forming devices 47L, 47R are provided with two slide shafts 63A, 63B, but this is not limited thereto and the configuration may include one or three or more slide shafts. When one slide shaft is provided, it is preferable that there is also one slide bearing. In this case, to prevent the slide bearing from rotating relative to the slide shaft, it is preferable that the slide shaft is a linear guide with a cross section that is approximately square, U-shaped, or H-shaped, etc., and that the slide bearing is a linear bushing combined with this.

[0076] Furthermore, the present invention can be applied to packaging machines other than the horizontal form-fill-seal packaging machine 10 (i.e., vertical form-fill-seal packaging machines). The above-described embodiments are examples for explaining the present invention, and are not intended to limit the scope of the present invention to only these embodiments. Those skilled in the art can make appropriate modifications within the scope of the present invention. [Explanation of symbols]

[0077] 10 Horizontal form-fill-seal machine 11 Supply conveyor 14 Drive sprocket 15 driven sprocket 16 Conveyor chain 17 Drive motor 18 Pusher 20 Packaging material feeder 21 Holder unit 22 Drive roller 23 Driven roller 24 Feed motor 25a, 25b Guide rollers 27 Snake adjustment mechanism 28 First drive unit 29 Tube maker 30 Clamping and conveying device 31 Support plate 32, 33 Film feed roller 34 Feed motor 35 Center seal device 36, 37 Seal roller 38 Seal Motor 39 Slit 40 End seal device 41, 42 Seal block 43, 44 Holder 45L, 45R guide shaft 46 Approach / separation mechanism 47L, 47R forming device 48 Support Block 49 Control Unit 51 Base plate 51 52L, 52R cylinder 61 Plate Cam 62 fixed frame 63A, 63B slide shaft 64 Gusset claw unit 65 Actuator 65A Piston Rod 66 screws 67 Sliding surface 67A Sliding contact start surface 67B Slope 67C Sliding end surface 68 screws 69 Connecting member 71 Gusset claw 72 Cam follower 72A Rotating shaft 73A, 73B bearings 74 frames 74A Gusset claw support 74B bearing holder 74C Connection hole 74D female screw hole 74E Through hole 75 plunger 75A plunger pin 75B coil spring 75C Case 75D knob 75E male thread 76A, 76B Claw part 77 Connecting member 78 screws 81A Cylindrical part 81B flange 82 screws

Claims

1. A gusset forming device that forms gussets in a cylindrical strip packaging material in accordance with the contact and separation movement of a pair of seal blocks that seal the cylindrical strip packaging material on both sides in a conveying direction, a slide shaft extending in a first direction perpendicular to the conveying direction; a gusset claw unit that moves in the first direction along the slide shaft; an actuator that pushes and pulls the gusset claw unit in the first direction, The gusset claw unit is a frame connected to the actuator; a gusset claw fixed to the frame with its tip facing the packaging strip and being pushed and pulled by the actuator to form the gusset in the packaging strip; a slide bearing fixed to the frame and fitted to the slide shaft to guide the movement of the gusset claw unit in the first direction, The gusset forming device is characterized in that the gusset claw unit is configured so that the frame, the gusset claw, and the slide bearing are integrated and the slide bearing can be inserted and removed from the slide shaft.

2. The gusset forming device according to claim 1, the actuator includes a connecting member connected to the frame, The frame is formed with a connection hole into which the connection member is inserted, The gusset claw unit includes a plunger provided at a position facing the connection hole, The plunger a plunger pin provided so as to be able to protrude and retract in a second direction perpendicular to the first direction between a protruding position protruding into the connection hole and a retracted position retracted from the connection hole; a biasing member that biases the plunger pin toward the protruding position, the connecting member has a through hole formed therein that penetrates in the second direction, A gusset forming device characterized in that the plunger pin enters the through hole with a gap formed between it and the inner wall defining the through hole, thereby preventing the connection member from coming off the connection hole.

3. The gusset forming device according to claim 1, The slide shafts are each extended in the first direction and are arranged in pairs at an interval in a third direction perpendicular to the first direction, The gusset forming device is characterized in that the actuator is located between the two slide shafts in the third direction.

4. The gusset forming device according to claim 1, The gusset forming device is characterized in that the slide bearing is a linear bushing having a plurality of rolling elements arranged along the first direction on an inner surface that slides against the slide shaft.

5. The gusset forming device according to claim 1, The gusset claws are a pair of claws provided on both sides of the seal block in the conveying direction; a connecting member that supports the pair of claw portions and is fixed to the frame,

6. The gusset forming device according to claim 1, a plate cam that moves in a third direction perpendicular to the first direction in conjunction with one of the seal blocks; a cam follower supported by the frame and switchable between an engagement state in which the cam is engaged with the plate cam by pushing or pulling the actuator and a release state in which the engagement is released, A gusset forming device characterized in that the cam follower and the plate cam are in the engaged state, and the plate cam guides the cam follower, causing the gusset claw unit to move in the first direction in accordance with the movement of the seal block.

7. A form-fill-seal packaging machine that fills products into bags formed from a strip-shaped packaging material, a cylinder former for overlapping both widthwise ends of the strip-shaped packaging material to form it into a cylindrical shape; a first sealing device that seals both ends of the strip-shaped packaging material that has been overlapped by the tube former; a second sealing device that seals both sides of a bag containing a product from the strip-shaped packaging material formed into a cylindrical shape by the first sealing device; 2. A bag-making, filling, and packaging machine comprising the gusset forming device according to claim 1, wherein a gusset is formed in the strip-shaped packaging material in accordance with the approaching and separating movement of the pair of seal blocks of the second sealing device.

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